Various dispensers are used to dispense curable materials such as sealants, caulks, and glues. Disposable cartridges may be mounted on a gun or the container may be of the type needing to be squeezed to dispense the material. A tapered, plastic nozzle of the container is selectively cut at the desired angle to form a nozzle tip orifice of the desired size. When using a gun, a trigger is squeezed to advance a piston of the gun against a plug of the cartridge. The plug moves into the cartridge to dispense the flowable material through the orifice. In addition to caulking type dispensing tubes, curable material is sometimes in one-piece molded tubes where the nozzle is molded into the tube. The curable material is sealed inside the tube by heat sealing the tube walls much like a toothpaste tube.
Standardized cartridges and squeeze containers, while providing economic packaging of flowable materials, generally are not sized precisely for the desired use. Consequently, a quantity of flowable material remains in partially-dispensed containers between uses. Capping the nozzle tip is important between uses to prevent leakage, but perhaps more importantly to prevent the material in the nozzle tip from curing thus potentially rendering the rest of the uncured material unusable.
Various caps have been used to block the opened nozzle tip with limited success. Many containers have a smooth tapered nozzle that conventional caps cannot adequately seal against. Conventional caps therefore allow air to contact the curable material. Over a short time of hours to weeks, the material in the nozzle, and perhaps the entire container, hardens and the nozzle becomes plugged. The user must resort to somehow clearing a flow path through the nozzle or the container may even become unusable.
Efforts to provide an air-tight seal to prevent this hardening include installing a nail, tape, plastic caps or other object into or on the nozzle tip. However, it is difficult to obtain a good seal and often the flowable material hardens nonetheless. In addition, it is inconvenient to procure a number of objects of varying diameters to accommodate variations in the diameter of the nozzle tip orifice.
Consequently, there exists a significant need for selectively sealing partially-dispensed containers of curable material. Ideally, an economical cap should be provided having the ability to seal various tapered nozzles that have been cut in different locations to yield discharge orifices of different diameter.